The existing vacuum glass is roughly divided into two kinds according to different modes of forming vacuum: the first one, compounding of two glass plates and sealing of peripheries of the two glass plates are both performed in a vacuum chamber, and vacuum is naturally formed in the sealed gap between the two glass plates after sealing; and the second one, the two glass plates are first compounded, then the peripheries of the glass plates are sealed, then the sealed gap between the glass plates is vacuumized through a pump-out hole preformed on one glass plate, and the pump-out hole is sealed after pumping, thus completing making of the vacuum glass. For the second vacuum glass, sealing of the pump-out hole is a last step for making the vacuum glass, and whether the pump-out hole is sealed reliably and whether the sealing structure is compact and firm are directly related to the quality of the vacuum glass, related to whether the later use of the vacuum glass is convenient and related to whether the vacuum glass is attractive, so the sealing of the pump-out hole of the vacuum glass becomes a crucial step for making the vacuum glass.